Re: WG ACTION: 2 weeks to discuss [LL63] Text could be more specific

> From: "Stuart Cheshire" <[email protected]>
> 
> Replace
> 
>    A device that implements both IPv4 Link-Local and a DHCPv4 client
>    should not alter  the behavior of the DHCPv4 client to accommodate
>    IPv4 Link-Local  configuration. In particular configuration of an
>    IPv4 Link-Local address,  whether or not a DHCP server is currently
>    responding, is not sufficient  reason to unconfigure a valid DHCP
>    lease, to stop the DHCP client from  attempting to acquire a new IP
>    address, to change DHCP timeouts or to  change the behavior of the
>    DHCP state machine in any other way.
> 
>    Several early implementations of IPv4 Link-Local have modified the
>    DHCP  state machine in an attempt to make IPv4 Link-Local more
>    reliable, and the  field experience we have gained from this has
>    shown that it does not work  - reliability of DHCP service is
>    significantly reduced.   If increased reliability of IPv4 Link-Local
>    is desired, we recommend that the IPv4 Link-Local state machine track
>    the DHCP client state machine and, in cases where it is not certain
>    that the DHCP-assigned address is correct, the  IPv4 Link-Local state
>    machine acquire an IPv4 Link-Local address without causing the DHCP
>    state machine to relinquish its address.
> 
>    Further discussion of this issue is provided in [DNAv4].
> 
> with just
> 
>    A device that implements both IPv4 Link-Local and a DHCPv4 client
>    should not alter the behavior of the DHCPv4 client to accommodate
>    IPv4 Link-Local configuration. In particular configuration of an
>    IPv4 Link-Local address, whether or not a DHCP server is currently
>    responding, is not sufficient reason to unconfigure a valid DHCP
>    lease, to stop the DHCP client from attempting to acquire a new IP
>    address, to change DHCP timeouts or to change the behavior of the
>    DHCP state machine in any other way.

This is omitting a specific recommendation as well as the unspecified example you objected to.

Whether just one or more implementations have made the mistake is irrelevant - it has been established as a mistake and useful guidance is provided.

However, this reads to me like a worry that unspecified "bad" former implementations may become erroneously associated with particular companies.

If this is the case, I could accept changing the first part of the offending paragraph:

   Several early implementations of IPv4 Link-Local have modified the
   DHCP  state machine in an attempt to make IPv4 Link-Local more
   reliable, and the  field experience we have gained from this has
   shown that it does not work  - reliability of DHCP service is
   significantly reduced.

To:

   Field experience has shown that modifying the DHCP state machine
   in an attempt to make IPv4 Link-Local more reliable does not work
   - reliability of DHCP service is significantly reduced.

Philip